Referring to FIGS. 7˜10, a conventional ratchet wrench 50 includes a handle 52 and an annular head 54 formed at an end of the handle 52. The annular head 52 defines a circular space 56, a crescent space 58 communicated with the circular space 56, a groove 60 in a side thereof and a recess 62 communicated with the groove.
A spring 64 and a ball detent 66 are put in the recess 62.
A direction switch 68 is put in and can be moved along the groove 60. A friction plate 70 is formed on the direction switch 68 for frictional contact with a user's finger. The direction switch 68 defines two recesses 72 and 74 in a side and a space 76 in an opposite side. The ball detent 66 is put in the recess 72 or 74 for keeping the direction switch 68 in one of two positions. The friction plate 70 defines an aperture 80 communicated with the space 76.
A V-shaped elastic element 80 includes two helical ends 82 and 84. The V-shaped elastic element 78 is put in the space 76.
As best shown in FIG. 8, a tab 86 is inserted in the space 76 for preventing the elastic element 80 from faltering in the space 76. The tab 86 defines an aperture 88.
A pin 90 is fit in the apertures 78 and 88 and put between the helical ends 82 and 84 so as to avoid the elastic element 80 escaping the space 76.
A pawl 92 includes two recesses 94 and 96 defined in a side and teeth 98 formed on an opposite side. The pawl 92 is put in the crescent space 58. The helical end 82 can be put in the recess 94, or the helical end 84 in the recess 96.
An annular gear 100 is put in the circular space 56. The annular gear 100 includes teeth 102 formed on an external side thereof for engagement with the teeth 98.
Referring to FIG. 9, the direction switch 68 is moved to a right-hand end of the groove 60 so that the ball detent 66 enters the recess 74. Via the elastic element 80, a right-hand end of the pawl 92 is moved to a right-hand end of the crescent space 58. Thus, the annular head 10 can drive the annular gear 100 clockwise, but not vice versa.
Referring to FIG. 10, the direction switch 68 is moved to a left-hand end of the groove 60 so that the ball detent 66 enters the recess 74. Via the elastic element 80, a left-hand end of the pawl 92 is moved to a left-hand end of the crescent space 58. Thus, the annular head 10 can drive the annular gear 100 counterclockwise, but not vice versa.
This conventional ratchet wrench 50 includes many elements. Many of its elements require fine fabrication, e.g., the direction switch 68 and the elastic element 80. It takes a lot of time to fabricate these elements. It also takes a lot time to assemble these elements. This conventional ratchet wrench 50 is very complicated in structure. As result, the cost of manufacturing of this conventional ratchet wrench 50 is high.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.